The present invention relates to an improvement in an electronic keyboard or similar electronic musical instrument having an automatic rhythm playing function and, more particularly, to an electronic musical instrument capable of performing improvisation or ad lib by using keys which lie in a particular range on a keyboard.
Some electronic musical instruments such as an electronic keyboard are provided with an automatic rhythm playing capability. The automatic rhythm playing capability is such that when a chord form is pressed by keys that lie in a particular range, for example, a bass and chord accompaniment is automatically developed. The system may be simplified such that a bass and chord accompaniment, for example, is developed in a particular rhythm without resorting to the manipulation of the keys. However, the automatic rhythm playing function available with the prior art electronic musical instruments is limited to "automatic rhythm play" and "automatic rhythm accompaniment coincident with automatic rhythm play", i.e., it cannot play a melody automatically and, hence, an operator has to play a melody part. More specifically, a melody play matching an automatic rhythm play cannot be affected without resorting to the actual manipulation of keys. Such an electronic musical instrument lacking an improvising function estranges persons who are interested in the instrument but not well trained musically, giving rise to a serious problem in the aspect of cultivation of artistic sentiments.